Extension-bit holder



April 28,' 1925.

F. voJQAcnz EXTENSION'BIT HOLDER Filed oct. 1e, 1922 vHy Y ATTORN Y Patented Apr. 28, 1925. i

` nenn oscila neen, or HILLsIDE, New

EXTENSION-BIT HOLDER.

Application led October 161, 1922. l Serial No. 594,760.

To aZZ whom t may concern: y

Be it` known that I, Fnnn OSCAR RACE, *a

citizen of the United States, and a resident of Hillside, county of Union, and State ot New Jersey, have invented anew and useful improvement in Extension-Bit Holders, of which the following is a specification.

My `invention relatesto an extension bit holder for use by electricians and others, which is of extreme simplicity and cheapness, readily manufactured and highlyeifective in operation, and is of extremely slender proportions so as to avoid objectionable bulkiness common to holders heretofore used for such purpose.

Other objects of the invention will appear from the following` description.

i ln the drawings 1 have shown certain embodimentsof the invention, but it is to be understood that same are only for illustration and for affording an understanding of the invention and not forlimitation thereof. ln said drawings, Fig. 1 is a side view showing the extension bit insertedin the holder and ready to be clamped therein. Fig. 2 is alongitudinal section `of the device shown in Fig. 1, the bit being clamped in place in the holder. Fig. 3 is a perspective view with parts broken away, the relation of parts being the same as in Fig. 2. Fig. 4L is a cross-sectional view on line 44-4, Fig. 1. Figs. 5 and 6 are cross-sectional detail views taken respectively on the lines .5 5 and 6--6` of Fig. 2. Fig. 7 isa plan view of one of the spring clamping fingers for the holder shown in Figs. 146. Fig. 8 is a .longitudi` nal sectional view of a modified form` of `holder, dispensing with the use of ,spring` fingers, with a bit inserted 1n the holder to` be clamped in place. therein. Fig. 9 is a view similar to Fig. 8 with the blt clamped in place. Fig. 1() 1s a transverse section on line 10-10, Fig. 8, and Fig. 11 is a trans verse section on line 11-11, Fig. 9.

rllhe rod vor stem 10 has a shank 11 adapted to be inserted in an ordinary brace. Said stem 10 is threaded at its outer end 12 and such threaded portion is provided with an elongated, preferably cylindrical knurled nut 13, which preferably has thev portion 141 of its bore screw threaded, and the portion 15 thereof somewhat enlarged ir vorder `to `unduly great length.

`rivet 1T, as shown in Fig. 5.

relieve this portion of the bore and to avoid making the screw threaded bore portion of At the outer end of said stem10, same is provided with a head 16, which is securely fastened in place in such manner as to provide a rigid connection and avoid turning of the headk relative to the rod l0. Such connection may be formed, for example, by forming the eX` treme end of the rod 10 into a flat sided The head 16 is here shown as made up of a plunalitj,7 of thin punchings of sheet metal, which is a simple and convenient `way to construct the head, but such head may be otherwise formed, if desired, as by being made from a single piece of thicker material.

An elongated slender tubular sleeve 18 is y 20, 2O of sleeve 18, so that saine enter the groove 19 at opposite-sides thereof, as shown clearly in the cross sectional view of Fig. 6.

Provision is made for enabling the sleeve 18 to have a sliding movement on the head 16 and at the same time to prevent relative rotative movement between these parts. ln the form shown, the head 1G is provided with four equally spaced longitudinally extending grooves 21, arranged 90. degrees apart throughout the circumference thereof, and the sleeve 18 is provided with four inwardly extending splines 22 adapted to enter the grooves 21. y Splines 22 are preferably formedby striking inwardly the sheet metal material of the sleeve 18, leaving the groove portions 23 on the exterior of sleeve 18; Said inwardly extending spline members 22 also have the additional function of keeping the spring lingers 24, provided to clamp the extension bit 25, properly spaced apart. Said spring fingersQa have a reduced portion 26 at the inner end thereof, and salu reduced portions 26 are received in slots 2T provided to receive same in the head 16 and spaced equidistant intermediate the spline members 22, said spring lingers being held seated in the notches 27 by means of the encircling sleeve 18. Such spring fingers 24 are inwardly bowed at the center portions thereof as shown at 2S, 2S and diverge at their outer ends 29, 29 and are provided at such outer ends with inwardly turned jaws 30, SO, which are rounded out as shown at 81, 31, Fig. 4, in order to lit closely about the stem 32 ot the extension bit 25 when drawn together.

rlhe operation of the holder shown in Figs. 1-7 will be readily understood .'trom the foregoing. I'Vhen the extension bit is to be inserted, nut 13 is screwed backen the stem 10, carrying the sleeve 1S with it` and permitting the tingers 24 to project the-rebeyond, as shown inFig. 1. The bit being inserted, nut 13 is screwed in the opposite direction, thereby pushingl the sleeve 18 outwardly over the spring fingers 24, forcing su'ch spring lingers together and securel-y clamping the bit 25. In the clamped position, it will be seen that the bit is firmly held against turning as each ot the clampingl lingers 24 engaging same is confined between the splines 22 on the opposite sides thereof, thereby preventing any rotation ot' the bit and clamping-means within the sleeve 1S. Release ot the bit is secured by turning the nut 13 to move the sleevef18 inwardly on the stem 10, whereupon the spring .tingers 24, being freed, spring outwardly and separate from one another, permitting the bit shank 33 to be readily and easily withdrawn, and avoiding any binding or holding action at such times.

In the modilication orp Figs. Skll, the. spring lingers 24 dispensed with and the head 16 is elongated and provided with a four sided tapered recess'34 to receive the butt end of the bit shank 33. The sleeve 18 is provided with splines 22 which enter notches 21 in the head 16, thereby permitting` sleeve 18 to move longitudinally with respect to head 16, but preventing relative rotary movementoiLl such parts. The outer end ot sleeve 18 is of a formation adapted to permit the bit shank 33 to be inserted therein. but to prevent outward movementv ot substautialiy arcuate form when viewed from the outer end of the sleeve 1S and serve to prevent the bit shank trom moving out of ythe sleeve 1S when same is turned axially through one-eighth oit a revolution into the dotted line position ci Fig. 11. The screwed tapered recess 34 in head 1G has its squared faces 88 so arranged that when the bit shank 83 is seated therein the squared sides o1 the shank occupy the dotted line position oit Fig. 11 and the shank is prevented from moving outwardly with respect to the sleeve 18 by the arcuate lip portions 3G. vWhen the nut 3 is screwed back to the position shown in Fig. S it is readily possible to insert the extension bit 32 in place, its square shank 33 passing'v through the square opening 37 provided for the purpose, whereupon it can readily be given a one-eighth turn from the position shown .in F ig.` 8 to the rotative position shown in Fig.` 9, and upon nut 13 beingv screwed inwardly, the shank 33 becomes firmly seated in the squared recess provided therefor iny the head'l, and is firmly and securely clamped in place, the parts occupying the-relative position shown in Fig. 9.

It is to ybe understood thatthe illustrative embodiments ot my invention shown herewith are intended only for affording an understandin g of the invention and that changes and modifications may be resorted to within the scope ot my claims by which the invention is deiined, without departing from my invention.

I claim:

1. In anv extension bit holder, a screw threaded stem adapted to be inserted in a brace, a nut on the screw threaded part thereof, a head rigidly secured to the outer end-oi' the stem, said head having two sets of groovesftherein, a sleeve having inwardly extending splines adapted to enter one set ot said grooves, said sleeve having means of connection to they nut so that longitudinal movement ot the latter iscommunicated to the former, a plurality ot spring. clamping fingers received and held in the second set ot grooves in said head and also received between and held from turning l.by said splines, said spring lingers having clan'iping jaws adapted to clamp an extension bit within said sleeve.

2. In an extension bit holder, a stem adapted to be held in a brace and screw threaded near its outer end, a nut on the screw threaded part havingva cylindrical peripherally grooved portion near its outer end, a head rigidly secured on the outer end of the stem and having two sets ot grooves therein, the grooves in the two sets being arranged to alternate. with one another, an elongated sleeve slidable on the head and having a plurality ot spaced splines struck inwardly therefrom to enter and run in one ot the sets of grooves in the head, said sleeve extending over the nut and having inwardl)v extending portions to enter the groove therein; a plurality ot spring fingers having reduced'portions entering the second set ot grooves in thehead and held thereon between the head and the inner wall ot the sleeve, `seid fingere being normally yspring; tensioned to separate from one another and thereby tend to expand at their outer ends `:und being received between and held from turning with vrespect to the sleeve by the splines thereof and' inwardly extending jaws formed on said `fingers in the neighborthe sleeve Lund its stern projecting therefrom. l0 v y In testimony whereof, I have signed my naine here-to.

F. OSCAR RACE. 

